Percussion arrangements

ABSTRACT

A percussion arrangement for piezo-electric apparatus especially for lighters comprising a piezo-electric element, a pivotal hammer resiliently urged into contact with the piezo-electric element and a rotatable cam in contact with the hammer for raising the hammer above the piezo-electric element and allowing the hammer to drop onto the piezo-electric element by virtue of the resilient action on the hammer. The cam comprises a plurality of sectors each having a first portion whose profile extends from the axis of rotation of the cam so as to move the hammer away from the piezo-electric element and a second portion whose profile approaches the axis of rotation to allow the hammer to drop onto the piezo-electric element. A pivotal thumb piece is resiliently urged away from the cam and hammer and a link is pivotally connected to the thumb piece and bears against the cam to effect rotation thereof when the thumb piece is displaced. The cam is freely rotatable and carries spindles, the link acting on one spindle when the user depresses the thumb piece to turn the cam, the link then passing to the succeeding spindle when the thumb piece is released and elevated. The cam is therefore freely rotatable and is disconnected from the link at the instant when the hammer approaches the piezo-electric element to strike the same.

United States Patent [191 Duetze 1 Feb. 18, 1975 1 PERCUSSION ARRANGEMENTS [76] Inventor: Karl Heinz Duetze,

Cessenas-Servier, SaintJorioz, France 74410 [22] Filed: Sept. 19, 1973 [21] Appl. No.: 398,801

[30] Foreign Application Priority Data Sept. 27, 1972 France 72.34166 [56] References Cited UNITED STATES PATENTS 10/1958 Derwin 310/87 X 6/1968 Goto .1 310/87 X 3,506,386 4/1970 Goto 431/255 3,724,993 4/1973 Goto 310/87 X FOREIGN PATENTS OR APPLICATIONS 712,803 8/1952 Great Britain 3l7/DIG. 11

Primary Examiner-Mark O. Budd Attorney, Agent, or FirmEric H. Waters [57] ABSTRACT A percussion arrangement for piezo-electric apparatus especially for lighters comprising a piezo-electric ele ment, a pivotal hammer resiliently urged into contact with the piezo-electric element and a rotatable cam in contact with the hammer for raising the hammer above the piezo-electric element and allowing the hammer to drop onto the piezo-electric element by virtue of the resilient action on the hammer. The cam comprises a plurality of sectors each having a first portion whose profile extends from the axis of rotation of the cam so as to move the hammer away from the piezo-electric element and a second portion whose profile approaches the axis of rotation to allow the hammer to drop onto the piezo-electric element. A pivotal thumb piece is resiliently urged away from the cam and hammer and a link is pivotally connected to the thumb piece and bears against the cam to effect rotation thereof when the thumb piece is displaced. The cam is freely rotatable and carries spindles, the link acting on one spindle when the user depresses the thumb piece to turn the cam, the link then passing to the succeeding spindle when the thumb piece is released and elevated. The cam is therefore freely rotatable and is disconnected fromthe link at the instant when the hammer approaches the piezo-electric element to strike the same.

7 Claims, 3 Drawing Figures 1 PERCUSSION ARRANGEMENTS The present invention is concerned with a percussion arrangement for piezo-electric apparatus, in particular for lighters. The operation of piezo-electric apparatus is based on the well-known fact that the application of a force on the faces of piezo-electric elements, for example, quartz or other crystals or certain ceramics creates between the faces, under predetermined conditions, an electric voltage proportional to this force. In the case of a lighter this electric voltage creates a spark which ignites the combustible.

It has already been proposed to obtain this force by a cylindrical cam of oval cross section compressing the piezo-electric element by rolling in a rigid body under a manual action effected on a thumb piece. This system has the inconvenience of requiring precision machining which is laborious and moreover gives variable results with manual action so that the effect is not uniform.

To avoid the aforesaid inconveniences it has also been proposed to obtain the force by a hammer striking the piezo-electric element, the hammer being maintained in raised position by a cam which eliminates the control thumb piece but this requires that to ensure sudden release of the hammer the cam must have a sharp angle and this sharp angle is subject to rapid wear.

An object of this invention is to provide an arrangement which eliminates this major inconvenience.

The invention contemplates a percussion arrangement for piezo-electric apparatus in which the movement of a hammer is controlled by a cam with around profile. This round profile has a variable radius of curvature, but variable in continuous fashion with the exclusion of any angles.

Briefly, the percussion apparatus comprises, in known manner, on the one hand, a pivoting hammer urged towards the striking position by a spring and provided with a support surface and, on the other hand, a thumb piece urged towards the raised position by a spring and capable of being manually depressed; the support surface of the hammer is urged into contact against a free-wheeling rotatable cam comprising at least one sector which includes a first portion of increasing profile extending from the axis of rotation of the cam and on which is displaced the supporting surface to elevate the hammer while the cam turns, and a second portion of decreasing profile approaching the said axis of rotation and permitting the supporting surface to fall from the portion of increasing profile at the same time as the hammer falls onto the piezo-electric element, a kinematic uni-directional connection from the thumb piece towards the free-wheeling cam effecting turning of the free-wheeling cam as regards at least the first portion of the sector while the user depresses the said thumb piece.

In a particular embodiment of the invention, each sector presents a round profile comprising a first portion of increasing radius from a hollow to a projection and on which the supporting surface is displaced to raise the hammer and a second portion of decreasing radius from the said projection to a hollow along and on which the supporting surface moves to cause the free-wheeling cam to turn while the hammer falls.

Thus, in the position of rest of the percussion arrangement according to the invention, the hammer is maintained by its spring in a lower position, the support surface of the hammer rests in a hollow of the freewheeling cam and immobilizes the same; when the user depresses the thumb piece, the kinematic unidirectional connection effects turning of the freewheeling cam, the support surface of the hammer slides from the hollow to the projection and lifts the hammer; when the support surface arrives at the projection the position becomes unstable: the support surface causes the free-wheeling cam to turn and the hammer falls freely under the action of its spring to strike the piezoelectric element with constant energy whatever speed and force is effected by the user on the thumb piece and this constitutes an important advantage of the invention.

Preferably, but not essentially, the kinematic connection according to the invention includes on the said free-wheeling cam an abutment for each sector and an oscillating link supported by the thumb piece and urged resiliently towards the free-wheeling cam, the link engaging and moving one of the abutments during manual depression of the thumb piece then passing to the succeeding abutment while the spring of the thumb piece urges it to the raised position.

It is considered that the action by the link may be effected by a spring (as described later) or by traction, and that the link may be inherently resilient thus dispensing with a separate spring.

Preferably, but not essentially, the free-wheeling cam comprises three sectors and the two profile portions of each sector may be symmetric (as described later) or asymmetric.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings.

FIG. 1 is a longitudinal section of a percussion arrangement according to the invention;

FIG. 2 is a view of a detail of FIG. 1; and

FIG. 3 is similar to FIG. 1 without the return springs and without the piezo-electric element and showing the position (unstable) of the various components at the instant when the roller of the hammer passes from the first to the second portion of the profile of a sector of the cam.

Referring to FIG. 1, the percussion arrangement according to the invention is shown mounted in a support 1 of generally U-formation. A piezo-electric element 3 is screwed into the base of the U. At the mid-height of the support a hammer 5 is pivoted by its relatively straight handle 7 on a fixed axle 9 of the support 1, its relatively large head 11 being capable of striking the head of the piezo-electric element 3. A relatively strong helical spring 13 is symmetrically wound on the axle 9 on both sides of the handle 7 and is supported by a central loop 15 on the hammer 5 and by its two ends 17 on a strut 19 of the support 1. The handle 7 of the hammer 5 supports a transverse spindle 21 on which freely turn two symmetrical lateral wheels 23. Below the handle 7 of the hammer 5, a cam 25 is freely mounted on a fixed spindle 27 of the support 1. In this embodiment the free-wheeling cam 25 has three sectors, each sector covering an angle of and'in each sector the portion of increasing radius from a hollow 29 to a projection 31 is symmetrical with the portion of decreasing radius from the projection 31 to a hollow 29. The freewheeling cam is slightly less large than the support 1 and it is traversed by three transverse spindles 33 equiangularly spaced at l20 which turn freely and pass through it at each side (they also have a guiding function as will be described later). A thumb piece 37 is pivoted on axle 39 at the top of the support and has the form of an inverted U. It is urged into a raised position (shown in FIG. 1) by a helical spring 41 wound on the axle 39 and abutting the strut 19 and under the thumb piece 37. Two arcuate slots 43 formed on the limbs of the thumb piece 37 slide on a strut 45 of support 1 and limit the movement of the thumb piece. The latter has a transverse axle 47 on which pivots a stirrup 49 of inverted U-form urged by a light helical spring 51 wound on the axle 47 and abutting under the stirrup 49 and under the front of the thumb piece 37. The two depending limbs 53 of the stirrup 49 constitute two links which extend into the spaces between the freewheeling cam 25 and its two wheels 35 which guide them in the transverse sense. The links 53 at their lower ends (FIG. 2) are curved towards the free-wheeling cam 25 along a round path 55 followed by a vertical part 57 to form a hook 59 which can engage an end of one of the spindles 33 of the free-wheeling cam 25, the links also including a lower vertical part 61. The links form a drive means to rotate the cam as will be explained later.

The operation of this embodiment of the invention will now be described.

In the rest position which is shown in FIG. 1, the thumb piece 37 is supported in raised position by its spring 39, the strut 45 being at the lower end of the aperture 43; the links 53 of the stirrup 49 under the action of the spring 51 abut by their vertical lower parts 61 (FIG. 2) against the ends of one of the spindles 33 of the free-wheeling camZS; the hammer 5 under the action of the spring 13 rests with its wheels 23 in a hollow 29 of the free-wheeling cam 25 which is thus immobilized and the hammer head rests on the piezo-electric element 3.

When the user depresses the thumb piece 37, the links 53 descend and by their hooks 59 (FIG. 2) engage the ends of the spindle 33 causing it to rotate the freewheeling cam 25; the wheels 23 of the hammer 5 roll on the hollow 29 of the free-wheeling cam up to the projection 31 and the hammer 25 is elevated; there is thus obtained an unstable position as shown in FIG. 3. The wheels 23 of the hammer 5 clear the projection 31 pushing back the free-wheeling cam 25 by rolling towards the succeeding hollow 29 and the hammer head 11 strikes the piezo-electric element 3 under the sole action of its spring 13 and independently of the manner in which the user has depressed the thumb piece 37.

The free-wheeling cam 25 is immobilized by the wheels 23 coming to rest in the succeeding hollow 29. When the user releases the thumb piece 37 it is raised by its spring 41; the links 53 are moved towards the free-wheeling cam 25 by the spring 5] bearing under the ends of the succeeding spindle 33 of the cam 25 at first by the curved parts 55 (FIG. 2) then by the vertical parts 57 and finally by the lower vertical parts 61. The percussion arrangement once again takes up the position of rest (FIG. 1), the free-wheeling cam 25 having been rotated one third of a revolution.

What we claim is:

l. A percussion arrangement for piezo-electric apparatus, especially for lighters, comprising a piezoelectric element, a pivotal hammer resiliently urged into contact with the piezo-electric element, a rotatable cam in contact with the hammer and which comprises at least one sector having a first portion whose profile extends from the axis of rotation of the cam so as to move the hammer away from the piezo-electric element, and a second portion whose profile approaches the axis of rotation to allow the hammer to drop onto the piezo-electric element, a pivotal thumb piece resiliently urged away from the hammer and cam, and drive means coupled to said thumb piece for bearing against said cam to effect rotation of the cam when the thumb piece is displaced, the cam being freely rotatable and being disconnected from the drive means at the instant when the hammer approaches the piezo-electric element to strike the same.

2. An arrangement according to claim 1, wherein said sector of the free-wheeling cam is constituted by a tooth presenting a flank of increasing profile and a reentrant flank which permits the support surface of the hammer to fall freely upstream of the flank of increasing profile.

3. An arrangement according to claim 1, in which the hammer support surface is constituted by at least one wheel adapted to roll on the profile of the freewheeling cam.

4. An arrangement according to claim 1 in which said cam sector has a round profile and said first portion is of increasing radius from a hollow to a projection and along which is displaced a support surface of the hammer and said second portion is of decreasing radius from the projection to a succeeding hollow and on which the support surface rests to effect turning of the free-wheeling cam during descent of the hammer.

5. An arrangement according to claim 1 comprising a support of generally U-shape, the piezo-electric element being screwed into the base of the U, the hammer including a handle supporting an axis on which turn two symmetrical lateral wheels, the free-wheeling cam being traversed by three equi-angularly spaced spindles whose ends constitute the abutments, a stirrup in the form of an inverted U pivoted to the thumb piece and including two limbs which constitute the links the lower ends of which are curved towards the free-wheeling cam along a circular path followed by a vertical part to form a hook for engaging a spindle and then a recess including a lower vertical part.

6. An arrangement according to claim 1 comprising a uni-directional kinematic connection between the thumb piece and the cam inclusive of said drive means, said connection comprising an abutment for each cam sector and a link pivotably mounted on the thumb piece and resiliently urged against said thumb piece, the link acting on one of the said abutments when the user depresses the thumb piece then passing to the succeeding abutment when the thumb piece is released and elevated.

7. An arrangement according to claim 6, in which the free-wheeling cam comprises three sectors, the two portions of the profile of each sector being symmetrical, and the link being a thrust link urged against the cam by spring action.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 5,867,655 Dated February 18, 1975 Patent No.

Inventor(s) Karl Heinz Dietze It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the Title page, in item [:76] the inventors name should read Karl Heinz Dietze Signed and sealed this 27th day of May 1975.

(SEAL) Attest C. MARSHALL DANN RUTH C. I'IASON Commissioner of Patents and Trademarks Attesting Officer USCOMM-DC 60376-P69 u.s. GOVERNMENT PRINTING urncs: 93

FORM PO-105O (IO-69) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,867,655 Dated February 18, 1975 Inventor-(s) Karl Heinz Dietze It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the Title page, in item [76] the inventor's name should read Karl Heinz Dietze Signed and sealed this 27th day of May 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks FQRM PO-105O (10-69) USCOMNPDC Wands u.s. sovzmmzm PRINTING orncz; 930 

1. A percussion arrangement for piezo-electric apparatus, especially for lighters, comprising a piezo-electric element, a pivotal hammer resIliently urged into contact with the piezoelectric element, a rotatable cam in contact with the hammer and which comprises at least one sector having a first portion whose profile extends from the axis of rotation of the cam so as to move the hammer away from the piezo-electric element, and a second portion whose profile approaches the axis of rotation to allow the hammer to drop onto the piezo-electric element, a pivotal thumb piece resiliently urged away from the hammer and cam, and drive means coupled to said thumb piece for bearing against said cam to effect rotation of the cam when the thumb piece is displaced, the cam being freely rotatable and being disconnected from the drive means at the instant when the hammer approaches the piezo-electric element to strike the same.
 2. An arrangement according to claim 1, wherein said sector of the free-wheeling cam is constituted by a tooth presenting a flank of increasing profile and a re-entrant flank which permits the support surface of the hammer to fall freely upstream of the flank of increasing profile.
 3. An arrangement according to claim 1, in which the hammer support surface is constituted by at least one wheel adapted to roll on the profile of the free-wheeling cam.
 4. An arrangement according to claim 1 in which said cam sector has a round profile and said first portion is of increasing radius from a hollow to a projection and along which is displaced a support surface of the hammer and said second portion is of decreasing radius from the projection to a succeeding hollow and on which the support surface rests to effect turning of the free-wheeling cam during descent of the hammer.
 5. An arrangement according to claim 1 comprising a support of generally U-shape, the piezo-electric element being screwed into the base of the U, the hammer including a handle supporting an axis on which turn two symmetrical lateral wheels, the free-wheeling cam being traversed by three equi-angularly spaced spindles whose ends constitute the abutments, a stirrup in the form of an inverted U pivoted to the thumb piece and including two limbs which constitute the links the lower ends of which are curved towards the free-wheeling cam along a circular path followed by a vertical part to form a hook for engaging a spindle and then a recess including a lower vertical part.
 6. An arrangement according to claim 1 comprising a uni-directional kinematic connection between the thumb piece and the cam inclusive of said drive means, said connection comprising an abutment for each cam sector and a link pivotably mounted on the thumb piece and resiliently urged against said thumb piece, the link acting on one of the said abutments when the user depresses the thumb piece then passing to the succeeding abutment when the thumb piece is released and elevated.
 7. An arrangement according to claim 6, in which the free-wheeling cam comprises three sectors, the two portions of the profile of each sector being symmetrical, and the link being a thrust link urged against the cam by spring action. 